Suction box for a papermaking machine having multiple compartments formed by j-shaped elements

ABSTRACT

A suction box for the dewatering of felt carrying paper webs, the suction box being located above a traveling felt which carriers a paper web on its underside, the box including multiple internal compartments formed by longitudinally spaced elements formed in a J-shape to create water-receiving compartments which conduct the accumulated water to lateral drain troughs which depend below the water-receiving compartments and below the traveling felt and web. Shoes which are attached to the bottoms of the J-shaped elements form a base for the suction box and allow for transverse passageways therebetween for liquid to be drawn upwardly by suction drawn through a suction port attached to the top wall of the suction box.

3,708,390 TIPLE Jan. 2, 1973 K. v. KRAKE SUCTION BOX FOR A PAPERMAKING MACHINE HAVING MUL COMPARTMENTS FORMED BY J-SHAPED ELEMENTS Filed Sept. 14. 1970 7 Sheets-Sheet 1 Jan. 2, 1973 K. v. KRAKE 3,708,390

SUCTION BOX FOR A PAPERMAKING MACHINE HAVING MULTIPLE COMPARTMENTS FORMED BY J-SHAPED ELEMENTS Filed Sept. 14, 1970 7 Sheets-Sheet 2 N oE mobEww mm 8. mm 5 1 LWR A m rm v J .v a Q i Q 2 Q r 4 F N M 8w F////W//////////////////////////\X/ 3 m m w w Jill. 2, 1973 I v, KRAKE 3,708,390

suc'rxon BOX FOR A PAPERMAKING MACHINE HAVING MULTIPLE comma'rnnms FORMED BY J-SHAPED ELEMENTS Filed Sept. 14, 1970 7 Sheets-Sheet 3 Jan. 2, 1973 v, KRAKE 3,708,390 SUCTION BOX FOR A PAPERMAKING MACHINE HAVING MULTIPLE COMPARTMENTS FORMED BY J-SHAPED ELEMENTS Filed Sept. 14, 1970 7 Sheets-Sheet 4.

Jan. 2,, 1973 KRAKE 3,708,390

K. v. SUCTION BOX F A PAPERMAKING MACHINE A I MULTIPLE COMPAR NTS FORMED BY J-SHAPED E TS Filed Sept. 14, 1970 7 Sheets-Sheet 5 Jan. 2, 1973 K RAKE 3,708,390

V. K SUCTION BOX FOR A PAPERMAKING MACHINE HAVING MULTIPLE CQMPARTMENTS FORMED BY J- SHAPED ELEMENTS Filed Sept. 14, 1970 7 Sheets-Sheet 6 Jpfi. 2, 1973 K. v. KRAKE 3,708,390 SUCTION BOX FOR A PAPERMAKING MACHINE HAVING MULTIPLE COMPARTMENTS FORMED BY J-SHAPED ELEMENTS Filed Sept. 14. 1970 7 Sheets-Sheet 7 United States Patent SUCTION BOX FOR A PAPERMAKING MACHINE HAVING MULTIPLE COMPARTMENTS FORMED BY J-SHAPED' ELEMENTS Kenneth V. Kralre, Neenah, Wis., assignor to Kimberly- Clark Corporation, Neenah, Wis. Filed Sept. 14, 1970, Ser. No. 71,999 Int. Cl. DZlf 1/52 US. Cl. 162--374 8 Claims ABSTRACT OF THE DISCLOSURE A suction box for the dewatering of felt carrying paper webs, the suction box being located above a traveling felt which carries a paper web on its underside, the box including multiple internal compartments formed by longitudinally spaced elements formed in a J-shape to create water-receiving compartments which conduct the accumulated water to lateral drain troughs which depend below the water-receiving compartments and below the traveling feltand web. Shoes which are attached to the bottoms of the J-shaped elements form a base for the suction box and allow for transverse passageways therebetween for liquid to be drawn upwardly by suction drawn through a suction port attached to the top wall of the suction box.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to suction boxes for use in connection with papermaking machines. More specifically, the invention is concerned with a suction box for the dewatering of felt carrying paper webs. Still more specifically, the invention is directed to a suction box having a structural arrangement which provides for effecting dewatering by withdrawing the water upwardly through a traveling felt carrying a paper web on its underside.

The invention with relation to the prior art It is known to use stationary suction boxes in the dewatering of paper webs. A very frequent use is in the dewatering of newly formed Webs by passing the forming screen over the suction box. The (web carried on the upper screen side is subjected to the action of the vacuum pressure through the screen and flow of water to the suction box is facilitated.

I contemplate the provision of a suction box which will operate very suitably on the upper side of a felt which carries the wet paper web on its lower side. I provide in my suction box a combination of elements which serve to permit presentation of the felt to the box without significant felt wear and which also serve to separate the removed water from the air flow involved in the vacuum application.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more fully understood by reference to the following detailed description and accompanying drawings wherein:

FIG. 1 is an elevational view illustrating the combination of wet paper web and felt passing through a plurality of suction boxes in general accordance with the invention;

FIG. 2 is an elevational view partially in section and with portions broken away illustrating a suction box of FIG. 1 in more detail;

FIG. 3 is a view taken on line 3-3 of FIG. 2;

FIG. 4 is a much enlarged perspective view partially in section and with parts broken away illustrating a corner zone of the suction box of FIG. 1;

FIG. 5 is a view similar to that of FIG. 4 with parts 3,708,390 Patented Jan. 2, 1973 broken away and illustrating more in detail the operation of the device;

FIG. 6 illustrates one form of a generally J-shaped element which serves as a channel for liquid drainage flow transversely of the device and also as a compartment divider;

FIG. 7 is a perspective view of a shoe which cooperates with the J-shaped element illustrated in FIG. 6 and provides a base structure of the suction box;

FIG. 8 is a schematic view in section illustrating the cooperative relationship of a traveling felt and wet paper web with the base of the suction box; and

FIG. 9 illustrates a further arrangement for effecting drainage of liquid drawn into the suction box in the course of operation.

A PREFERRED EMBODIMENT OF THE INVENTION IN DETAIL In basic aspect the suction box includes a base with which the web carrying felt is in contact and openings in the base communicate with compartments under vacuum pressure to aid dewatering of the felt-web combination. In the mentioned compartments water is deposited and flows laterally of the box to depending drain troughs. Elements of a generally J-shape cooperate to define the compartments and to provide adequate seals to inhibit air flow other than through the traveling felt. The elements of J-shape extend transversely of the box and, depending upon the specific location in the box, may vary in dimension laterally of the box. The J-shaped elements carry replaceable shoes which engage the felt and provide the wear surface as well as scaling functions.

Referring to the drawings more in detail, the numeral 1 (FIGS. 1 and 8) designates a usual papermakers felt carrying on its underside a newly formed wet paper web 2. The felt and web as illustrated by the direction of the arrow in FIG. 1 are passing from left to right and centrally (FIG. 3) through a plurality of suction boxes indicated generally at 3.

The suction boxes 3 each may comprise, as illustrated more particularly in FIG. 2, a plurality of upper compartments 4a, 4b and 4c extending the full width of the box. Additionally, the box may include on each side a plurality of lower compartments 4d, 4e and 4 depending laterally of the central portion of the box. The upper compartments 4a, 4b, 4c may be connected through a suitable fitting 5 in the form of a suction port to a vacuum line in conventional manner and the upper compartments are themselves connected together through horizontally extending apertures 6a, 6b in the vertical divider supports 6. For the purpose of balancing air flow under vacuum conditions, the openings 6a, 6b may be of different size but such is not necessary to operation of the device. Suitably, the opening at the left designated 61: is larger than the opening designated 6b (FIG. 2). The lower compartments of each set 4d, 4e and 4] each exhaust as indicated by the legend in FIG. 2 to a separator which serves in conventional manner to aid in separation of water from air. The lower compartments 4d, 4e and 4 of a set are connected together for inter-communication through adjustable sized openings to be discussed more fully hereinafter.

Referring again to FIG. 2, vertically extending holes 7 serve to communicate each of the upper compartments 4a, 4b and 4c with a plurality of compartments 8 intermediate the height of the suction box. The compartments 8 are themselves vacuum zones and are in communication with the felt and web passing through the box by means of passageways 9*. In operation, under the influence of vacuum, liquid is drawn from the Wet felt and web upwardly through the passageway 9 to the compartment 8 and is deposited in the bottom of channel 10 on bottom Wall 14 as noted below (FIG. 2). Air drawn upwardly with the water is separated from the water in compartments 8.

The central compartment structures lengthwise of the suction box are suitably formed by the use of a plurality of essentially J-shaped elements indicated generally at 11 in FIGS. 2, 4, 5 and 6. Each element 11 (FIG. 6) includes an upwardly rearwardly sloping side wall 12, a key 13 on the upper end of the side wall, a bottom wall 14 delimiting the channel 10, a key 16 and a forward upwardly rearwardly angled flange or arm 15. In effect, the arm and side wall 12 define the water-receiving compartment wall at 14.

The forward end of the suction box suitably is of a slightly different construction involving an upwardly extending side wall 17, a bottom wall 18, an upwardly extending and rearwardly sloping wall 19, an upper key 20 and a lower key 21. At the right hand end of the box, as illustrated in FIG. 2, the structure includes an upwardly extending wall 22, a base wall 23 and an upwardly extending rearwardly angled partial wall or arm 24. This latter structure defines a compartment having a lower key 25 and an upper key 20a. Water drawn into this latter mentioned compartment passes transversely of the suction box in the same manner as water passes transversely in the channels 10 to the sides of the box where it is withdrawn from the equipment. The upper keys 20, 20a and 13 of the partition members described are received in and supported by a plate 26 (FIGS. 2 and 3). Plate 26 includes the apertures 7 already mentioned and extends the full width and length of the suction box.

In some instances where the suction box is both long and wide, additional support for the plate 26 is provided by web supports as indicated at 27 in FIGS. 2 and 9. In such instance the space between the support 27 and the immediately forward or preceding wall 12 (FIG. 2) of a J-shaped element is a dead Zone not exposed to vacuum conditions.

The suction box has a top wall 29 and outer vertically depending end walls 30. The numeral 33 designates outer longitudinally extending opposed front and back walls as each having openings 34 which are cut-out slots to provide convenient access to the suction box. The slots 34 are each covered by a transparent plastic plate element 35 (FIG. 3) for permitting viewing of the interior of the box.

Drainage troughs are defined in each longitudinal side of the suction box by the walls 36 which cooperate with walls 33 and bottom walls 31 for the purpose. The walls 36 are relatively short in height and project upwardly from the base walls 31 longitudinally with the base walls as indicated particularly in FIGS. 2 to 4. The side drainage troughs include an upper wall 37 (FIG. 3) which is open over much of its length (FIG. 4) to the waterreceiving compartments of the J-shaped members. Also, the wall 37 serves as a component of a seal to provide for inhibiting breakage of vacuum between the traveling felt and the troughs. Some few J-shaped members as designated at 11a in FIG. 9 extend the full width of the box transversely between opposed front and back walls 33 while others terminate at walls 37 as now noted more particularly.

A transparent plastic window member 38 secured to the sides of J bar members 11 by cap screws or the like (FIG. 5) and serving as a side boundary to the waterreceiving compartments also aids in maintaining vacuum and is itself provided with outlet ports designated at 49 (FIGS. 3 and 5) to provide for flow of water from the compartments to the drain troughs. A plurality of these window members 38 are provided in spaced relationship along the length of the box and each abuts laterally against a wall 12 of a J-shaped member 11 (FIGS. 2 and 5) to provide an air seal. The J members so abutted by the the members 38 each themselves extend laterally of the suction box to the wall 37 as shown particularly in FIGS. 2 and 5. Only select ones of the J elements as designated by the numeral 11a (FIG. 9) extend the full lateral width of the suction box 3 and abut against the outer transparent plastic plate element 35. A purpose of so extending the members 11a is to insure against leakage around the ends of compartments such as that at 4d and 4e, and 4e and 4 Drain holes 50 in the extremities of member 11a provide for water flow directly to the last mentioned compartments and then to the separator. Passage of air between compartments is undesirable in these areas as it may tend to prevent an unbalance in the system. Partitions 39 each provided with a plurality of apertures 39a divide the suction box lengthwise into the compartments 4d, 4e and 4f. Slides 28 provided with openings 28a adapted to index or partially index with apertures 39a provide for fiow between the latter mentioned compartments.

The J elements through their keys 13 are slidably mounted in Ways 40 of the plate 26 as most clearly shown in FIGS. 2 and 4. The J elements also each slidably receive over the full width of the box a shoe as at 41, which shoe itself engages and seals with the ledges 37 of the oppositely disposed drainage troughs or, in the case of elements 11a, with walls 33. The J-shaped elements 11a and shoes 41a extend full width and are associated with the partitions 39 seal ingly engaging the partitions as illustrated in FIG. 9. The element 41b is similar in width to the element 41 but is shaped to conform to the suction box forward end. Similarly, the element 410 at the right hand end (FIG. 2) is shaped to conform to the right hand end of the box. The shoe may thus have any suitable cross-section to effect a sealing engagement with a wall as, for example, the seal of wall support 27 with ledge 37 (FIG. 9). The shoes 41, 41a, 41b, 41c taken together provide a base on which the felt I is carried.

Each shoe 41 is provided with ways 42 at opposite ends of the shoe. Each way 42 lies on the forward face of a shoe and is arranged to receive a seal member 43 (FIGS. 4 and 5). For this purpose a way 42 extends inwardly of the ledge 37 over the felt passing through the box (FIG. 4). Each member 43 includes the forwardly disposed sealing section 44 which engages ledge 37 and on its rearward face the member carries the key 45 for receipt in a shoe 41. The section 44 bears firmly against the upper ledge 37 of the drainage trough (FIG. 4) providing a sealing relation against air admission around the felt. Each seal member 43 is relatively short and adjustably positionable in a way but sufi'lcient in dimension to extend transversely from the ledge 37 and across the gap formed by a J element 11 and the ledge and to extend over part of the traveling felt 1. The shoe itself suitably does not extend so far inwardly as the traveling web 2 (FIG. 4). A plurality of shoes, one associated with each J-shaped member, effectively seal the suction box from air leakage.

Referring now particularly to FIG. 8, the numeral 47 designates an upwardly and rearwardly tapering wall of each shoe 41. Each upwardly tapering wall defines a spacing 48 which communicates with a passageway to the vacuum zone 8 and is so arranged that it provides that the traveling felt I will be drawn only slightly toward the interior of the suction box by vacuum application. In fact, a vacuum condition is created by the felt traveling at the wall 47 by reason of felt speed, and this vacuum provides an assist in water removal from the felt. Water moving to the felt surface under vacuum pressure influence is removed from the felt surface by contact of the felt with the doctor edge 51 of a following shoe, that is, an edge provided on the exit side of an opening to the channel and vacuum zone. The arrangement described is thus not only efiicient but provides for minimum felt distortion and a minimum load on the driving equipment.

A particular advantage of the structural arrangement described is that each vacuum zone 8 may be simply sealed off independently of all others if vacuum in a particular zone is not required. Additionally, such may be accomplished while operating by simply substituting for a shoe 41a, for example, a shoe which is appropriately shaped to bridge and close an opening to a channel. Such is shown in association with support 27 in FIG. 2.

I have found that for long wear characteristics, it is desirable to provide the shoes which engage the felt and form the wear surface to be of resinous material such as high density polyethylene. Other materials function to achieve the purpose of dewatering a traveling combination of wet felt and Wet web, and such materials may, of course, be formed to serve as readily replaceable shoes. Accordingly, I do not wish to be limited to a particular material but do indicate my experience to favor the polyethylene.

As many apparently widely dilferent embodiments of i this invention may be made without departing from the spirit and scope thereof, it is to be understood that I do not limit myself to the specific embodiments thereof except as defined in the appended claims.

I claim:

1. A suction boxcomprising a box including a top wall and end walls and having a longitudinally extending base with transverse passageways and over the outer surface of which base a felt to be dewatered may be drawn, the said top wall having a suction port for the application of suction pressure to the suction box interior, means communicating the passage-ways of the base with said suction port comprising a plate having holes therein and extending the width and length of the box below said top wall and defining with the top wall a spacing, said lattermentioned means also including multiple element means having water-receiving compartments interiorly of the suction box and said holes communicating the said waterreceiving compartments with the said spacing and suction port, and at least one drain trough laterally of the base depending below the water-receiving compartments and communicable therewith for draining the compartments.

2. A suction box as claimed in claim 1 and in which each of the multiple elements comprises a member of generally J-shape having its lower portion serving as the 6 water-receiving compartment as the conduit to the drain trough.

3. A suction box as claimed in claim 2 and in which the said base of the suction box includes a shoe on the underside of the J-shaped member extending transversely of the box with the J-shaped member and disposed in slidable relation to the said J-shaped member.

4. A suction box as claimed in claim 1 and in which the suction box has adjacent J-shaped members disposed longitudinally in succession such that a long arm of a first J-shaped member defines with a short arm of a next succeeding J-shaped member a channel leading to the said water-receiving compartments, and said channel communicates with a passageway of the said box.

5. A suction box according to claim 4 and in which at least one J-shaped member has drain hole means communicating directly with a drain trough.

6. A suction box as claimed in claim 4 and in which each J-shaped member has on its underside a shoe and adjacent shoes define the passageway to the channel.

7. A suction box as claimed in claim 4 and in which each J-shaped member has on its underside a wear shoe for engaging a papermakers traveling felt and at least one pair of adjacent shoes define a passageway to the channel, and at least one other pair of shoes bridging and closing a channel.

8. A suction box as claimed in claim 1 and in which the said spacing has vertical supports subdividing the spacing, said supports including horizontal extending apertures.

References Cited UNITED STATES PATENTS 3,526,574 9/1970 Beachler et a1. 162-358 X 1,688,216 10/1928 We'nZel l62364 2,928,465 3/1960 Wrist l62-374 X 2,881,675 4/1959 Thomas 162-203 S. LEON BASHORE, Primary Examiner R. H. TUSHIN, Assistant Examiner US. Cl. X.R. 162363 

